Improvement in circuit-closers for electrical burglar-alarms and signals



EDWIN. HOLMES & HENRY C. ROOME.

" Improvement in Circuit Closers for Electrical Burgleir Alarms andSignals. N0. 120,744, Patented Nov- 7,1871.

Jig-l. i A 1+ z 1 3 5 E g 34 UNITED STATES EDWIN HOLMES, OF BROOKLYN,NEW YORK, AND HENRY O. ROOME, OF JERSEY crTY, NEW JEnsEY.

IMPROVEMENT IN CIRCUIT-ULOSERS FOR ELECTRICAL BURGLAR-ALARMS ANDSIGNALS.

Specification forming part of Letters Patent No. 120,744, dated November7, 1871.

To all whom it may concern:

Beit known that we, EDWIN HOLMES, of Brooklyn, in the county of Kingsand State of New York, and HENRY O. ROOME, of Jersey City, in the co1mtyof Hudson and State of New Jersey, have invented a new and usefulImprovement in Circuit- Olosers for Electrical Burglar-Alarms andSignals, of which the following is a full, clear, and

exact description, reference being had to the accompanying drawingforming part of this specification.

Our invention relates to circuit-closers for that class of burglar-alarms and signals which are operated by a difference in the flow of thecurrent of a closed circuit; and the invention consists in a permanentmagnet surrounded by one or more magnetic coils, thereby forming animproved circuit-closer. The invention likewise comprises a certaincombination of an armature with a circuit-closer, whereby thesynchronous opening of one circuit and closing of another is effected bythe action of said armature; and the invention furthermore includes acombination, with the permanent magnet, of a foil spring, whereby amorecomplete or perfect contact is obtained between said magnet and thepoint it makes and breaks circuit with.

Figure 1 represents an interior front view of an apparatus having ourinvention applied to it; Fig. 2, a vertical section through the line m xin Fig. 1; Fig. 3, avertical section through the line i y y in Fig. 2and Fig. 4, a diagram, showing the connection of the apparatus withcertain batteries and an alarm-bell.

Similar letters of reference indicate corresponding parts throughout theseveral figures.

D in the accompanying drawing is the permanent magnet surrounded orinclosed by one or more magnetic coils, O. F is an adjusting-screw,arranged so that when the coils O are not charged it will always be inmetallic connection with the magnet D by the impinging or embedding ofit, as produced by the deflection of the magnet against or within a finefoil springs, one end of which is soldered to the magnet. Said spring isused to insure electrical contact with the screw F, and, by making saidspring of thin foil, this is more efi'ectually and certainlyaccomplished than when more contact of the spring and end of the screwis relied upon, as dust or dirt getting upon the end of the screw wouldarrest or interfere with the passage of the current, whereas a springmade of thin foil allows of the point of the screw embedding itselftherein; consequently the fouling of the endof the screw would be of butlittleor no importance. E is a similar screw,but so arranged andadjusted that when the usual current is passing through the coils O themagnet D will .almost, but not quite, touch it. H representsa pair ofelectro-magnets, provided with an armature, I, which is notched at itsone end so as to engage witha hook upon the arm of a drop, K, pivoted,as at b, and so arranged and constructed that when released by thearmature I it will fall upon and move downward an upright arm of acircuit-breaker, L, and cause the latter to rest upon a pin, 0. Saidcircuit-breaker L is pivoted intermediately of its length, so that whenits one end is in contact with the pin 0 its other end will be thrown upand made to break contact with a pin or stop, d. The circuit-breaker Lhas its contact with the pin or stop 0 broken and its contact with thepin d established by a spring, 0, when relieved from the weight of thedrop K. The pivot of L is connected, by a wire, 43, with screw-cups 4and 5, and connection continued from thence, by the wire i, to one poleat the batteryB; and the pin or stop at is connected, by a wire, it, tothe wire of the electro-magnets H, and connection continued from thence,by a wire, m, to the adjusting-screws E and F. The pin 0 is connected,by a wire, I, to a signal or alarm-bell, W, and from thence, by saidwire, I, through a screw-cup, b, to the other pole of the battery B. Ais a battery, having one of its poles connected, by awire, 0, to theplace or structure to be guarded or signal to be made, from whence saidwire returns to a screw-cup, l, and, passing through the magnetic coilsO, emerges at a screw-cup, 2, andfrom thence to the other pole of thebattery A. The permanent magnet D is in connection. by a wire, n,through a screw-cup, 3, with the battery B.

The operation of the invention as appliedto a burglar-alarm, which isthe purpose here selected for illustration, is as follows: When thepoints or places to be guarded are closed and secured, a current willflow from the battery A through the wire or circuit 0 and magnetic coilsG. This will cause the magnet D to approach closely to, but notquite'touch, the adjusting-screw E, at the same time breaking contactbetween the magnet D and screw F. The drop K is set to engage with thearmature I. This being the condition, the circuitcloser is then inproper position for protecting the exposed points or places, and themagnet D, as in Fig. 3, touches neither of the adjusting-screws E and F.If any attempt be made to enter the point or place guarded by meanswhich cause the flow of the current through the coils O to be increased,then the magnet D Will instantaneously deflect to a contact with theadjusting-screw E. This will close the circuit i of the battery B, andthe current, passing through magnet H and attracting the armature I,will release the drop K, which,

in falling upon the upright arm of the circuitbreaker L, will breakcontact between the latter and the pin d and establish contact betweensaid circuit-breaker and the pin or stop 0, thereby completing thecircuit 1 through the alarm W and the battery B and sounding acontinuous alarm. If any attempt be made to enter the point or placeguarded by means which cause the flow of the current through the circuit0 to be broken or diminished, the magnet D would fall and establishcontact with the adjusting screw F, and thus close the circuit i m ofthe battery B and sound the alarm, as before.

While we prefer to use two batteries, A and B, as described, one batterymight be made to answer without changing the character or principle ofthe invention. Neither do we confine ourselves to making the magnet D ofitself close the circuit of the battery B, as it is obvious that saidmagnet might be made to carry or actuate an independent circuit-closerwith substantially the same effect; nor do we restrict ourselves to theuse of the adjusting-screws E and F, as a like contact with the magnet Dcan be made in various ways or by other means without changing theinvention.

Instead of the alarm-bell, too, any other audible or visible signalmight be used.

What we here claim, and desired to secure by Letters Patent, is

1. The circuit-closer, consisting of the permanent magnet D, surroundedor inclosed by the magnetic coil or coils O 0, charged by a primarycircuit, and operating substantially as described, for the purpose setforth.

2. The combination of the armature Iwith the circuit-closer L, wherebythe synchronous opening of one circuit and the closing of another by theaction of said armature is effected, substantially as specified.

3. The combination of the foil spring 3 with the magnet D, essentiallyas described.

EDWIN HOLMES. H. O. ROOME.

Witnesses:

R. W. Tom), JAMES ToMNEY.

